JP2004281007A - Magnetic transfer device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic transfer device which improves transfer precision. <P>SOLUTION: The magnetic transfer device which brings a master medium having servo information recorded thereon into close contact with a slave medium and applying an external magnetic field to transfer servo information from the master medium to the slave medium comprises; a re-transfer means which rotates only the master medium at a prescribed angle to transfer servo information on the master medium to the slave medium again after transferring servo information from the master medium to the slave medium; an amplitude value comparison means which reproduces transferred servo information on the slave medium in track units and compares amplitude values of servo information with a prescribed value; and a servo information selection means which selects servo information for use in the slave medium from servo information of which the amplitude values are larger than the prescribed value as a comparison result. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a magnetic transfer device that transfers predetermined servo information to a magnetic disk medium mounted on a magnetic storage device widely used as an external storage device of a computer.
[0002]
[Prior art]
In a hard disk drive, which is a typical magnetic disk device, the areal recording density is increased by increasing the track density and the linear recording density. The increasing trend of the track density exceeds the increasing trend of the linear recording density, and achieves the improvement of the areal recording density.
In order to realize a high recording density, a tracking servo technology of a head for accurately tracking a narrow track of a magnetoresistive element type head (MR head, GMR head, TMR head, etc.) also plays an important role. .
[0003]
In a hard disk drive using such tracking servo technology, servo information such as tracking servo address information (track data and sector data) is recorded on a disk medium. Writing and reading of these signals require high precision. At present, in a hard disk drive, formatting is performed in which servo information is written on a disk medium by a servo writer incorporating a laser length measuring device for detecting a head position. Problems include that it takes time to write signals to a large number of tracks while positioning the head with high accuracy, and that the servo writer is expensive.
[0004]
Therefore, instead of using a servo writer for formatting, a method of superimposing a master medium on which servo information is written and a magnetic disk medium to be formatted and applying an external magnetic field to collectively transfer information on the master medium to the magnetic disk medium Began to take place. (For example, see Patent Document 1)
In the transfer method using the master medium, magnetic transfer is performed by supplying an external magnetic field while the master medium is in close contact with the magnetic disk medium to be preformatted, and a magnetic recording medium having predetermined servo information is formed in a short time. Since it can be manufactured, the manufacturing process can be simplified and the cost can be reduced.
[0005]
[Patent Document 1]
JP-A-7-78337
[Problems to be solved by the invention]
However, the transfer method using the master medium is based on the characteristics of the master medium itself, such as “variation” of the magnetic pattern when the master medium is formed, or the adhesion between the master medium and a magnetic disk medium as a product. This has a great effect on the quality of the transferred signal.
[0007]
FIG. 6 shows an explanatory diagram of a signal of a conventional example.
Some of the transferred servo signals have poor signal quality, and if this magnetic disk medium is used as it is, an error will occur. As described above, when recording is performed using the transfer technique, problems specific to transfer such as transfer unevenness occur.
Accordingly, an object of the present invention is to provide a magnetic transfer device that improves transfer accuracy.
[0008]
[Means for Solving the Problems]
A magnetic transfer device for transferring servo information from a master medium to a slave medium by bringing a master medium having servo information recorded thereon into close contact with a slave medium and applying an external magnetic field, wherein the servo information is transferred from the master medium to the slave medium. When the transfer of the master medium is completed, only the master medium is rotated by a predetermined angle and the servo information of the master medium is again transferred to the slave medium. An amplitude value comparing means for comparing an amplitude value of information with a predetermined value, and a servo information selecting means for selecting servo information to be used in the slave medium from servo information larger than the predetermined value as a result of the comparison. .
[0009]
With this configuration, it is possible to select servo information having a normal signal from among a plurality of transfer results without selecting servo information having a deterioration signal generated due to transfer unevenness, so that a slave with higher accuracy is improved. Production of media becomes possible. A magnetic transfer apparatus for transferring servo information from a master medium to a slave medium by bringing a master medium on which servo information is recorded into close contact with a slave medium and applying an external magnetic field, wherein a plurality of servo information positions are different. When the transfer of the servo information from the master medium to the slave medium is completed, only the master medium is replaced, and a plurality of master re-transfer means for transferring the servo information of the master medium to the slave medium again, and the transferred slave The servo information on the medium is reproduced for each track, and the amplitude value comparing means for comparing the amplitude value of the servo information with a predetermined value, and, as a result of the comparison, the servo information used in the slave medium from the servo information larger than the predetermined value. And servo information selecting means for selecting.
[0010]
With this configuration, it is possible to select servo information having a normal signal from among a plurality of transfer results without selecting servo information having a deterioration signal generated due to transfer unevenness, so that a slave with higher accuracy is improved. Production of media becomes possible.
Further, the servo information selecting means is further configured to reproduce the address information of the servo information and select the servo information which does not cause a reading error.
[0011]
With this configuration, it is determined whether or not address information can be normally read for a plurality of transfer results having normal signal levels, so that a slave medium with higher accuracy can be manufactured.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 shows a configuration diagram of the magnetic transfer apparatus of the embodiment.
The magnetic transfer device 1 includes a medium rotation exchange unit 2, a medium unit 3, a transfer magnetic unit 4, a reproduction signal selection unit 5, and a rotation exchange instruction unit 6.
The medium rotation exchange unit 2 causes the master medium 11 and the slave medium 12 to come into close contact with each other and rotate in a predetermined direction according to an instruction from the rotation exchange instruction unit 6. Further, only the master medium 11 is rotated by a predetermined angle with respect to the slave medium 12. The exchange of the master medium 11 is also performed.
[0013]
The medium unit 3 includes a master medium 11 and a slave medium 12.
As shown in FIG. 3, the transfer magnetic unit 4 moves the magnet 14 with the positioner 13 closer to the upper side of the master medium 11 with a predetermined gap, and rotates the master medium 11 and the slave 11 which rotate as the magnet 14 moves in the X-axis direction. An external magnetic field is applied to the medium 12, and the servo information formed by the master medium 11 is transferred to the slave medium 12.
[0014]
After the end of the transfer, the reproduction signal selection unit 5 reproduces the signal of the slave medium 12, confirms the amplitude value of the signal for each track, and restores the data of the servo information. Then, servo information is selected according to a predetermined standard.
The predetermined criterion is, for example, the signal strength, the youngest number when the number of times of transfer is counted from “1”, and the like.
[0015]
The rotation exchange instruction unit 6 instructs the medium rotation exchange unit 2 to rotate, instructs the master medium 11 to rotate only a predetermined angle with respect to the slave medium 12 when the transfer is completed, and exchanges the transfer master medium 11. Make instructions.
FIG. 2 shows a flow chart of the process of the magnetic transfer apparatus of the embodiment.
The description will be made by taking two transfers as an example.
[0016]
First, the master medium 11 and the slave medium 12, which is a magnetic recording medium to be transferred, are set in the medium rotation exchange unit 2 (Step S11).
Next, the first transfer from the master medium 11 to the slave medium 12 is performed (Step S12).
FIG. 3 is an explanatory diagram of the magnetic transfer.
[0017]
In the magnetic transfer process, a magnetic disk medium is brought into close contact with a master medium 11 having servo information as a slave medium 12, and is rotated at a predetermined rotation speed in the same direction. Next, by moving the magnet 14 in the X-axis direction by the positioner 13 of the transfer magnetic unit 4, an external magnetic field is applied to the master medium 11 and the slave medium 12, and the servo information of the master medium is transferred to the slave medium 12. You.
[0018]
Next, when the first transfer is completed, the master medium 11 is separated from the slave medium 12, and only the master medium 11 is rotated by a predetermined angle.
Next, the master medium 11 is brought into close contact with the slave medium 12 again. Then, the second transfer is performed (S13 step).
Instead of rotating the same master medium by a predetermined angle, when the first transfer is completed, the master medium 11 is separated from the slave medium 12 and the position of the servo information of the master medium 11 used for the first transfer is changed. There is also a method of replacing the master medium 11 formed at a position different from the above.
[0019]
Another example of the master medium exchange method is as follows.
First, for a plurality of master media 11, servo information is transferred to the slave medium 12 in advance, the servo signals are measured, and the characteristics of transfer unevenness in track units are obtained. Next, from the plurality of master media 11, a combination of master media 11 that does not cause transfer unevenness for the same track is selected. Then, the plurality of master media 11 of this combination is used as the master media 11 for transfer. With this method, transfer with higher accuracy can be performed.
[0020]
FIG. 4 is an explanatory diagram of the two transfer processes.
By the first transfer, the servo information is transferred from the master medium 11 shown in FIG. 4A to the slave medium 12 shown in b.
At the time of the second transfer, the master medium 11 is rotated by a predetermined angle with respect to the master medium 11 shown at a as shown at c. Then, when the master medium 11 is transferred, the first transfer indicated by the dotted line and the second transfer indicated by the solid line are transferred onto the same slave medium 12, as indicated by d.
[0021]
When the transfer is completed, 1 is set to the track number N (step S14).
Next, the master medium 11 is separated from the slave medium 12, the magnetic head (not shown) is brought close to the slave medium 12, the servo signal of the track number N is read, and the amplitude value is measured (S15 step).
For example, the amplitude value of the signal of the servo address information is measured.
[0022]
When a servo signal is read, whether the servo signal has been transferred for the first time or the servo signal transferred for the second time can be identified by, for example, adding a mark for position detection to the slave medium in advance, and detecting the mark. Then, the first servo signal can be identified by the first time and the subsequent servo signals can be identified by the second time.
Next, the first measurement result of the servo signal 1 is obtained (S16 step).
[0023]
Next, the amplitude value is compared with a predetermined value (S17 step).
If the amplitude value is larger than the predetermined value, it is determined that the signal is good, and the servo signal 1 is adopted (Step S18), and the second servo signal 2 is deleted.
At this time, as a method of selecting a servo signal, a method of selecting a signal having a smaller number of times of transfer is selected.
[0024]
If the first amplitude value is not larger than the predetermined amplitude value, the second measurement result of the servo signal 2 is obtained (Step S19).
Next, it is confirmed whether or not the amplitude value of the second servo signal 2 is larger than a predetermined amplitude value (Step S20).
If the amplitude value is larger than the predetermined value, the second signal is selected and the first servo information 1 is erased (step S21). If both are not at the predetermined level, an error notification is made (step S22).
[0025]
It is checked whether N is the end of the track (step S23).
If not the last, N = N + 1, and the process returns to step S15 to repeat the processing.
When N is the last, the process ends.
FIG. 5 is an explanatory diagram of the signal selection processing.
When the servo signal transfer master medium is transferred twice at different angles, servo signals are recorded at different positions in the time domain as shown in FIG. If the first transfer servo signal 1 has deteriorated due to uneven transfer, the second transfer servo signal 2 is used.
[0026]
In the case of multiple transfers, if the second servo signal is also deteriorated, the servo signal of that track will be lost and the position information will not be obtained by using the subsequent servo signal. Can be prevented. In the case of multiple transfers, a plurality of servo signals whose amplitude values exceed a predetermined level may be acquired. In this case, for example, selection is performed by adopting the one with the smallest number of transfers. I do.
[0027]
If the amplitude value is larger than the predetermined value, the address information of the servo information, that is, the gray code is read, and it is determined whether or not the data can be read normally. Thereby, the transfer unevenness can be detected with high accuracy, so that the transfer accuracy can be further improved.
Also, the characteristics of the master medium 11 are measured in advance, and the magnetizing conditions such as the pressing pressure when applying the master medium 11 and the magnetic flux density to be applied are changed for each rotation of a predetermined angle in accordance with the characteristics, and the transfer is performed. By doing so, the transfer accuracy can be improved.
[0028]
【The invention's effect】
According to the present invention, it is possible to reduce the rate of occurrence of defective products due to transfer unevenness of a magnetic disk medium and to reduce costs.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a magnetic transfer device according to an embodiment; FIG. 2 is a flowchart of a process of the magnetic transfer device according to the embodiment; FIG. 3 is an explanatory diagram of magnetic transfer; FIG. FIG. 5 is an explanatory diagram of a signal selection process. FIG. 6 is an explanatory diagram of a signal in a conventional example.
REFERENCE SIGNS LIST 1 magnetic transfer device 2 medium rotation exchange unit 3 medium unit 4 transfer magnetic unit 5 reproduction signal selection unit 6 rotation exchange instruction unit 11 master medium 12 slave medium 13 positioner 14 magnet

Claims (3)

A magnetic transfer apparatus for transferring servo information from a master medium to a slave medium by bringing a master medium on which servo information is recorded into close contact with a slave medium and applying an external magnetic field,
When the transfer of the servo information from the master medium to the slave medium is completed, only the master medium is rotated by a predetermined angle, and the re-transfer unit that transfers the servo information of the master medium to the slave medium again,
Amplitude value comparing means for reproducing the transferred servo information on the slave medium in track units and comparing the amplitude value of the servo information with a predetermined value;
As a result of the comparison, servo information selecting means for selecting servo information to be used in the slave medium from servo information larger than a predetermined value,
A magnetic transfer device comprising: A magnetic transfer apparatus for transferring servo information from a master medium to a slave medium by bringing a master medium on which servo information is recorded into close contact with a slave medium and applying an external magnetic field,
A plurality of master media having different servo information positions;
When the transfer of the servo information from the master medium to the slave medium is completed, only the master medium is replaced, and a plurality of master retransfer means for transferring the servo information of the master medium to the slave medium again,
Amplitude value comparing means for reproducing the transferred servo information on the slave medium in track units and comparing the amplitude value of the servo information with a predetermined value;
As a result of the comparison, servo information selecting means for selecting servo information to be used in the slave medium from servo information larger than a predetermined value,
A magnetic transfer device comprising: 3. The magnetic transfer apparatus according to claim 1, wherein the servo information selecting unit further reproduces address information of the servo information and selects servo information that does not cause a read error.

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